Hi Nick

I have got the good spectrum, I have forgotten to normalize it.
Thank you so much.
Best regards.

Damien

On 31/10/2015 20:02, Nick Papior wrote:
If _everything_ is multiplied by 2, be aware of spin multiplicity. The transmission plot looks correct for a pristine system.

Secondly, how should the kpoints influence the result? There are no k-points in the device calculation.
If you mean in the electrodes, then fine.


2015-10-31 19:53 GMT+01:00 Damien Tristant <[email protected] <mailto:[email protected]>>:

    Dear Nick

    Thanks to your advice, I got the transmission spectrum (for 3 unit
    cells for right and left electrodes and 3 unit cells for device).
    Thank you very much. I have attached it. But I get 4 conduction
    channels at the Fermi level, instead of 2. I think that I have to
    play with parameters, the electronic temperature and Kpoints.
    Best regards.

    Damien


    On 30/10/2015 12:42, Nick Papior wrote:
    Great. Note, it will not print whether your device region is too
    small.

    2015-10-30 12:08 GMT+01:00 Damien Tristant
    <[email protected] <mailto:[email protected]>>:

        You are right Nick. When I use trunk version I get this message :

        WARNING: Connections across 2 unit cells or more in the
        transport direction.
        WARNING: This is inadvisable.
        WARNING: Please increase the electrode size in the transport
        direction.
        WARNING: Will proceed without further notice.



        On 30/10/2015 10:53, Nick Papior wrote:
        Well, all of those calculations have errors ;)

        1) Too short electrode, too short device
        2) Electrode (seems!) ok, too short device
        3) too short electrode, device (seems!) ok.

        The device *must* also be so big that no direct interaction
        between left-right takes place.

        You can check how the interaction table is by looking at the
        BONDS file. There has been several questions about this
        previously so search the mailing list.

        Lastly, you may want to try the trunk version which prints
        out if your electrode is too small.

        2015-10-30 10:31 GMT+01:00 Damien Tristant
        <[email protected] <mailto:[email protected]>>:

            Thank Nick Papior for your help, but unfortunately I got
            the same problem. Enclosed, I put the Transmission
            spectra and a picture of 3 different systems :
            - 96 atoms (1 unit cell for left electrode ; 1 unit cell
            for the sample ; 1 unit cell for the right electrode)
            - 160 atoms (2 unit cells for left electrode ; 1 unit
            cell for the sample ; 2 unit cells for the right electrode)
            - 128 atoms (1 unit cell for left electrode ; 2 unit
            cells for the sample ; 1 unit cell for the right electrode)
            As you can see the problem remains the same.
            May be the problem comes from the calcul of the complex
            contour?
            Best regards.

            Damien



            On 30/10/2015 07:23, Nick Papior wrote:

            Your electrode length is almost certainly too small,
            you must ensure principal cell connections, only. Try
            and double your electrode.

            --

            Kind regards Nick Papior

            On 30 Oct 2015 00:54, "Damien Tristant"
            <[email protected]
            <mailto:[email protected]>> wrote:

                Dear Everybody

                I am trying to obtain the transmission spectrum of
                a metallic carbon nanotube (8,8), carried out with
                Transiesta code. Unfortunately I don’t get the
                right spectrum (normally at the Fermi level I
                should see two conduction channels appear, I have
                attached the file).  I have changed the settings
                several times but the result is never correct. In
                the following there is my input files for the
                electrodes and the scattering zone.
                Could you please check if one of my parameters is
                wrong or if I forgot something?
                Thank you very much for your help.
                Best regards.

                Damien


                *Electrode :*


                # General system descriptors
                SystemName  cnt
                SystemLabel cnt
                NumberOfAtoms           32
                NumberOfSpecies         1
                %block ChemicalSpeciesLabel
                 1  6 C.gga   # Species index, atomic number,
                species label
                %endblock ChemicalSpeciesLabel

                #Unit cell for the calculation
                LatticeConstant 1 Ang
                %block LatticeVectors
                30.0000000000000000  0.0000000000000000
                 0.0000000000000000
                 0.0000000000000000 30.0000000000000000
                 0.0000000000000000
                 0.0000000000000000  0.0000000000000000
                 2.4617000000000000
                %endblock LatticeVectors
                # Lattice, coordinates, k-sampling
                AtomicCoordinatesFormat Fractional
                AtomicCoorFormatOut Fractional
                %block AtomicCoordinatesAndAtomicSpecies
                 0.684228479 0.500102328  -0.000000000 1
                 0.677959183 0.547673034 0.000000000 1
                 0.670191861 0.570611130 0.500000000 1
                 0.646198057 0.612161657 0.500000000 1
                 0.630219773 0.630352389 0.000000000 1
                 0.592119446 0.659511823  -0.000000000 1
                 0.570405934 0.670221335 0.500000000 1
                 0.524063557 0.682647265 0.500000001 1
                 0.499897672 0.684228479  -0.000000000 1
                 0.452326966 0.677959184  -0.000000000 1
                 0.429388870 0.670191860 0.500000000 1
                 0.387838343 0.646198057 0.500000000 1
                 0.369647610 0.630219773 0.000000000 1
                 0.340488177 0.592119446  -0.000000000 1
                 0.329778665 0.570405934 0.500000000 1
                 0.317352735 0.524063557 0.500000000 1
                 0.315771521 0.499897672 0.000000000 1
                 0.322040816 0.452326966  -0.000000000 1
                 0.329808140 0.429388870 0.500000000 1
                 0.353801943 0.387838343 0.500000000 1
                 0.369780227 0.369647611  -0.000000000 1
                 0.407880554 0.340488177 0.000000000 1
                 0.429594066 0.329778665 0.499999999 1
                 0.475936443 0.317352735 0.500000001 1
                 0.500102328 0.315771521  -0.000000000 1
                 0.547673034 0.322040816  -0.000000000 1
                 0.570611130 0.329808139 0.500000001 1
                 0.612161657 0.353801943 0.500000000 1
                 0.630352390 0.369780227  -0.000000000 1
                 0.659511823 0.407880554  -0.000000000 1
                 0.670221335 0.429594066 0.500000000 1
                 0.682647265 0.475936443 0.500000000 1
                %endblock AtomicCoordinatesAndAtomicSpecies

                # K-sampling (alternative specification using
                kgrid_cutoff)
                %block kgrid_Monkhorst_Pack
                 1   0   0   0.0
                 0   1   0   0.0
                 0   0 100 0.0
                %endblock kgrid_Monkhorst_Pack

                # Basis set definition
                PAO.BasisSize   DZP
                PAO.EnergyShift 50 meV
                PAO.SplitNorm   0.15

                # Real space grid
                MeshCutoff 200.0 Ry

                #Convergence of SCF
                MaxSCFIterations 100
                DM.MixingWeight  0.05
                DM.NumberPulay   10
                DM.Tolerance     0.0001

                # Eigenvalue problem: order-N or diagonalization
                SolutionMethod  diagon
                ElectronicTemperature   5.0 K


                # Density functional (Notice that Xc.authors and
                XC.functional)
                XC.functional           VDW
                XC.authors  KBM

                # Molecular Dynamics and relaxations
                MD.TypeOfRun            CG
                MD.NumCGsteps           0
                MD.VariableCell .false.
                MD.ConstantVolume       .true.

                # Output options
                WriteCoorInitial        .false.
                WriteCoorStep .true.
                WriteForces .false.
                WriteKpoints  .false.
                WriteEigenvalues        .false.
                WriteDM .true.
                WriteKbands .false.
                WriteBands  .false.
                WriteWaveFunctions      .true.
                WriteMullikenPop        0
                WriteCoorXmol .true.
                WriteCoorCerius         .true.
                WriteMDXmol .true.
                WriteMDhistory  .true.

                *Scattering zone :*

                # General system descriptors
                SystemName  cnt-system
                SystemLabel cnt-system
                NumberOfAtoms           96
                NumberOfSpecies         1
                %block ChemicalSpeciesLabel
                 1  6 C.gga   # Species index, atomic number,
                species label
                %endblock ChemicalSpeciesLabel

                #Unit cell for the calculation
                LatticeConstant 1 Ang
                %block LatticeVectors
                30.0000000000000000  0.0000000000000000
                 0.0000000000000000
                 0.0000000000000000 30.0000000000000000
                 0.0000000000000000
                 0.0000000000000000  0.0000000000000000
                 7.3851000000000000
                %endblock LatticeVectors
                # Lattice, coordinates, k-sampling
                AtomicCoordinatesFormat Fractional
                AtomicCoorFormatOut Fractional
                %block AtomicCoordinatesAndAtomicSpecies
                0.6842284789999999  0.5001023280000000
                 0.0000000000000000 1
                0.6779591830000000  0.5476730340000000
                 0.0000000000000000 1
                0.6701918610000001  0.5706111300000000
                 0.1666666666666667 1
                0.6461980570000000  0.6121616570000000
                 0.1666666666666667 1
                0.6302197730000000  0.6303523890000000
                 0.0000000000000000 1
                0.5921194460000000  0.6595118230000000
                 0.0000000000000000 1
                0.5704059339999999  0.6702213350000000
                 0.1666666666666667 1
                0.5240635570000000  0.6826472649999999
                 0.1666666670000000 1
                0.4998976720000000  0.6842284789999999
                 0.0000000000000000 1
                0.4523269660000000  0.6779591840000000
                 0.0000000000000000 1
                0.4293888700000000  0.6701918600000000
                 0.1666666666666667 1
                0.3878383430000000  0.6461980570000000
                 0.1666666666666667 1
                0.3696476100000000  0.6302197730000000
                 0.0000000000000000 1
                0.3404881770000000  0.5921194460000000
                 0.0000000000000000 1
                0.3297786650000000  0.5704059339999999
                 0.1666666666666667 1
                0.3173527350000000  0.5240635570000000
                 0.1666666666666667 1
                0.3157715210000000  0.4998976720000000
                 0.0000000000000000 1
                0.3220408160000000  0.4523269660000000
                 0.0000000000000000 1
                0.3298081400000000  0.4293888700000000
                 0.1666666666666667 1
                0.3538019430000000  0.3878383430000000
                 0.1666666666666667 1
                0.3697802270000000  0.3696476110000000
                 0.0000000000000000 1
                0.4078805540000000  0.3404881770000000
                 0.0000000000000000 1
                0.4295940660000000  0.3297786650000000
                 0.1666666663333333 1
                0.4759364430000000  0.3173527350000000
                 0.1666666670000000 1
                0.5001023280000000  0.3157715210000000
                 0.0000000000000000 1
                0.5476730340000000  0.3220408160000000
                 0.0000000000000000 1
                0.5706111300000000  0.3298081390000000
                 0.1666666670000000 1
                0.6121616570000000  0.3538019430000000
                 0.1666666666666667 1
                0.6303523900000000  0.3697802270000000
                 0.0000000000000000 1
                0.6595118230000000  0.4078805540000000
                 0.0000000000000000 1
                0.6702213350000000  0.4295940660000000
                 0.1666666666666667 1
                0.6826472649999999  0.4759364430000000
                 0.1666666666666667 1
                0.6842284789999999  0.5001023280000000
                 0.3333333333333333 1
                0.6779591830000000  0.5476730340000000
                 0.3333333333333333 1
                0.6701918610000001  0.5706111300000000
                 0.5000000000000000 1
                0.6461980570000000  0.6121616570000000
                 0.5000000000000000 1
                0.6302197730000000  0.6303523890000000
                 0.3333333333333333 1
                0.5921194460000000  0.6595118230000000
                 0.3333333333333333 1
                0.5704059339999999  0.6702213350000000
                 0.5000000000000000 1
                0.5240635570000000  0.6826472649999999
                 0.5000000003333334 1
                0.4998976720000000  0.6842284789999999
                 0.3333333333333333 1
                0.4523269660000000  0.6779591840000000
                 0.3333333333333333 1
                0.4293888700000000  0.6701918600000000
                 0.5000000000000000 1
                0.3878383430000000  0.6461980570000000
                 0.5000000000000000 1
                0.3696476100000000  0.6302197730000000
                 0.3333333333333333 1
                0.3404881770000000  0.5921194460000000
                 0.3333333333333333 1
                0.3297786650000000  0.5704059339999999
                 0.5000000000000000 1
                0.3173527350000000  0.5240635570000000
                 0.5000000000000000 1
                0.3157715210000000  0.4998976720000000
                 0.3333333333333333 1
                0.3220408160000000  0.4523269660000000
                 0.3333333333333333 1
                0.3298081400000000  0.4293888700000000
                 0.5000000000000000 1
                0.3538019430000000  0.3878383430000000
                 0.5000000000000000 1
                0.3697802270000000  0.3696476110000000
                 0.3333333333333333 1
                0.4078805540000000  0.3404881770000000
                 0.3333333333333333 1
                0.4295940660000000  0.3297786650000000
                 0.4999999996666666 1
                0.4759364430000000  0.3173527350000000
                 0.5000000003333334 1
                0.5001023280000000  0.3157715210000000
                 0.3333333333333333 1
                0.5476730340000000  0.3220408160000000
                 0.3333333333333333 1
                0.5706111300000000  0.3298081390000000
                 0.5000000003333334 1
                0.6121616570000000  0.3538019430000000
                 0.5000000000000000 1
                0.6303523900000000  0.3697802270000000
                 0.3333333333333333 1
                0.6595118230000000  0.4078805540000000
                 0.3333333333333333 1
                0.6702213350000000  0.4295940660000000
                 0.5000000000000000 1
                0.6826472649999999  0.4759364430000000
                 0.5000000000000000 1
                0.6842284789999999  0.5001023280000000
                 0.6666666666666666 1
                0.6779591830000000  0.5476730340000000
                 0.6666666666666666 1
                0.6701918610000001  0.5706111300000000
                 0.8333333333333334 1
                0.6461980570000000  0.6121616570000000
                 0.8333333333333334 1
                0.6302197730000000  0.6303523890000000
                 0.6666666666666666 1
                0.5921194460000000  0.6595118230000000
                 0.6666666666666666 1
                0.5704059339999999  0.6702213350000000
                 0.8333333333333334 1
                0.5240635570000000  0.6826472649999999
                 0.8333333336666667 1
                0.4998976720000000  0.6842284789999999
                 0.6666666666666666 1
                0.4523269660000000  0.6779591840000000
                 0.6666666666666666 1
                0.4293888700000000  0.6701918600000000
                 0.8333333333333334 1
                0.3878383430000000  0.6461980570000000
                 0.8333333333333334 1
                0.3696476100000000  0.6302197730000000
                 0.6666666666666666 1
                0.3404881770000000  0.5921194460000000
                 0.6666666666666666 1
                0.3297786650000000  0.5704059339999999
                 0.8333333333333334 1
                0.3173527350000000  0.5240635570000000
                 0.8333333333333334 1
                0.3157715210000000  0.4998976720000000
                 0.6666666666666666 1
                0.3220408160000000  0.4523269660000000
                 0.6666666666666666 1
                0.3298081400000000  0.4293888700000000
                 0.8333333333333334 1
                0.3538019430000000  0.3878383430000000
                 0.8333333333333334 1
                0.3697802270000000  0.3696476110000000
                 0.6666666666666666 1
                0.4078805540000000  0.3404881770000000
                 0.6666666666666666 1
                0.4295940660000000  0.3297786650000000
                 0.8333333330000000 1
                0.4759364430000000  0.3173527350000000
                 0.8333333336666667 1
                0.5001023280000000  0.3157715210000000
                 0.6666666666666666 1
                0.5476730340000000  0.3220408160000000
                 0.6666666666666666 1
                0.5706111300000000  0.3298081390000000
                 0.8333333336666667 1
                0.6121616570000000  0.3538019430000000
                 0.8333333333333334 1
                0.6303523900000000  0.3697802270000000
                 0.6666666666666666 1
                0.6595118230000000  0.4078805540000000
                 0.6666666666666666 1
                0.6702213350000000  0.4295940660000000
                 0.8333333333333334 1
                0.6826472649999999  0.4759364430000000
                 0.8333333333333334 1
                %endblock AtomicCoordinatesAndAtomicSpecies

                # K-sampling (alternative specification using
                kgrid_cutoff)
                %block kgrid_Monkhorst_Pack
                 1   0   0   0.0
                 0   1   0   0.0
                 0   0   70  0.0
                %endblock kgrid_Monkhorst_Pack

                # Basis set definition
                PAO.BasisSize   DZP
                PAO.EnergyShift 50 meV
                PAO.SplitNorm   0.15

                # Real space grid
                MeshCutoff 200.0 Ry

                #Convergence of SCF
                MaxSCFIterations 100
                DM.MixingWeight  0.05
                DM.NumberPulay   10
                DM.Tolerance     0.0001
                DM.UseSaveDM     .true.

                # Eigenvalue problem: order-N or diagonalization
                SolutionMethod  transiesta
                ElectronicTemperature   5.0 K

                TS.WriteHS  .true.
                TS.NumUsedAtomsLeft  32
                TS.NumUsedAtomsRight 32
                TS.HSFileLeft   'cnt.TSHS'
                TS.HSFileRight  'cnt.TSHS'
                TS.TBT.HSFile 'cnt-system.TSHS'
                TS.TBT.Emin    -4.0 eV
                TS.TBT.Emax     4.0 eV
                TS.TBT.NPoints   200

                # Density functional (Notice that Xc.authors and
                XC.functional)
                XC.functional           VDW
                XC.authors  KBM

                # Molecular Dynamics and relaxations
                MD.TypeOfRun            CG
                MD.NumCGsteps           0
                MD.VariableCell .false.
                MD.ConstantVolume       .true.
                # Output options
                WriteCoorInitial        .false.
                WriteCoorStep .true.
                WriteForces .false.
                WriteKpoints  .false.
                WriteEigenvalues        .false.
                WriteDM .true.
                WriteKbands .false.
                WriteBands  .false.
                WriteWaveFunctions      .true.
                WriteMullikenPop        0
                WriteCoorXmol .true.
                WriteCoorCerius         .true.
                WriteMDXmol .true.
                WriteMDhistory  .true.





-- Kind regards Nick




-- Kind regards Nick




--
Kind regards Nick

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